A new extracorporeal shock wave lithotripsy technique employing spherical sector shock waves will be evaluated with respect to pulverizing human kidney stones and decreasing tissue damage. Experimental comparisons will be made with a commercial-like elliptic reflector-type, focused shock system. These will use a common electric arc energy supply, test tank, kidney stone and stimulant targets and tissue and ultra-high-resolution piezoelectric polymer shock-pressure-measuring instrumentation. The tests, designed to simulate human treatment conditions in several significant respects, will provide general performance information for the proposed system in controlled comparison with that for the most widely used type of shock wave generator in clinical lithotripters today. The results should provide the essential base for a subsequent Phase II in vivo model animal investigation. This research is expected to lead to a major change in mode of clinical treatment because of the potential for sharp reductions in patient injury, pain and treatment time.